WASHINGTON TIMES — Prosecutors decided last week not to charge former Secretary of State Hillary Clinton over her secret email server, but a federal court could still force her to testify under oath after a conservative law firm petitioned the judge to force her to talk.

Judicial Watch, which has been pursuing Mrs. Clinton’s emails for years through more than a dozen open-records lawsuits and has already subjected her top aides to depositions, petitioned Judge Emmet G. Sullivan on Friday to order Mrs. Clinton to talk. The group said there are questions only she can answer about how she handled her messages.

“It was her system. She was the primary driving force behind it and was its principal user,” Judicial Watch said in its court filing. “Without Secretary Clinton’s testimony, there can be no fair, rightful and conclusive answer to the court’s questions.”

Mrs. Clinton escaped legal jeopardy when FBI Director James B. Comey concluded that while she risked national security by mailing top-secret information on a server she kept at her home in New York, and while she may well have broken several federal laws, she was so unsophisticated in her understanding of technology and classification that she didn’t know what she was doing.

Speaking for the first time publicly about the findings, Mrs. Clinton said that if she was reckless with security, it was because she was trusting her top aides, who were sending her the material.